Endless abrasive device



July 16, 1940. B. GROB Y ENDLES S ABRAS IVE DEVICE Filed March 2, 1939 v w R #Plllml m m H n e B ATTORNEY.

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Patented July 16, 1940 UNITED STATES ENDLESS ABRASIVE DEVICE Benjamin Grob, Grafton, Wis., assignor of onehalf to Theodore Grob, Grafton, Wis.

Application March 2, 1939, Serial No. 259,428

6 Claims.

This invention relates to endless abrasive devices for use particularly in filing machines of the continuous motion type. Endless abrasive devices for this purpose ordinarily include a longitudinal succession of rigid file elements or the like, each attached usually intermediate their ends to a flexible endless carrier. The carrier is commonly in the form of a chain or band adapted to be trained about a pair of spaced supporting and driving pulleys, and the attachment of the file elements is such as to render one or both ends of each element free of the carrier, so as to permit the latter to follow the pulley contours, and yet to effect substantial alignment or realignment of the elements in their straight course of travel between pulleys.

One object of the present invention is to provide in an endless abrasive device of this character improved means for effecting accurate registration of adjacent ends of successive file elements during their straight course of travel between pulleys, and to accomplish that without penetrating, interrupting, or otherwise impairing the abrasive surfaces of the elements. Accurate alignment of the elements can be accomplished only by precise registration of adjacent ends of successive elements, and precise registration is essential to attaining the desired continuity of abrasive surface within the working I zone.

Other more specific objects and advantages will appear, expressed or implied, from the following description of two illustrative embodiments of the present invention.

In the accompanying drawing:

Figure 1 is a side elevation, partly in section, of an endless abrasive device constructed in accordance with this invention.

Fig. 2 is a front elevation thereof.

Fig. 3 is a transverse section taken substantially along the line 33 of Fig. 1.

Fig. 4 is a side elevation, partly in section, of a modified form of endless abrasive device embodying this invention.

The endless abrasive device shown in Figs. 1 to 3 comprises an endless carrier Ill in the form of a chain similar to that described in the Patent No. 1,958,477 to Theodore Grob and myself. That portion of the chain illustrated is intended, during operation, to pass downwardly from an upper pulley I I, through a fixed guide channel l2 in the working zone, to and about a lower pulley (not shown) and thence upwardly and over the pulley II. The chain shown comprises a seriesv of relative long channel links [3 and intermediate relatively short channel links M flexibly connected by links l5 disposed between the sides of the long and short channel links.

Each long link I3 constitutes a carrier for a longitudinally extended file element l6 securely fixed thereto and projecting beyond the ends thereof into overlapping relation with respect to the intermediate short links 14. The arrangement is such that during travel of the chain about each pulley the projecting ends I! of successive file elements assume positions separated from each other and outwardly from the intermediate links [4, but as the chain enters the straight line course between pulleys the adjacent file ends assume a close mutually abutting relation over and close to the adjacent intermediate link.

In this instance this approach of adjacent file ends toward an adjacent intermediate link, as the chain straightens out in leaving a pulley, is utilized to effect precise registration of those ends. In the form of device shown in Figs. 1 to 3, this is accomplished by the provision of an appropriate guide key l8 on each intermediate link 14 adapted to enter and closely interengage with appropriate guide slots IS in the file ends as those ends approach the adjacent intermediate link. In this instance each key I8 is formed by striking up a' portion'of the top or outer wall of the link I 4, and the correspondingly shaped slots 19 are preferably formed wholly within the back or under face of the'file ends so as to avoid any interruption in or mutilation of the outer abrasive surfaces of the file ends.

The sides of each key l8 and those of the coacting slots H! are preferably straight and parallel and of sufficiently close fitting relation to insure extremely accurate alignment of the file ends, although the upper edges or corners 20 of each key l8 are preferably slightly bevelled to facilitate entry thereof into the slots.

As indicated, particularly in Fig. 3, the several file elements l6 bear against and ride upon or along the forward edges 2| of the channel guide l2, the links i3 and I4 being of a depth to provide clearance 22 betweenthem and the base of the guide 12 and of a width to insure a close sliding fit between them and the sides of the guide. The short links M are preferably of less depth than the links l3 so as to provide clearances 23 between them and the overhanging ends I! of the file elements. These clearances 22 and 23 insure proper functioning in spite of the presence of fine chips or metallic dust resulting from the filing or abrasive action.

In the device shown in Fig. 4, the several file elements l6 are appropriately fixed to a steel pins I8 fixed to the band 10, each being dis-- posed to project into a guide slot l9 formed in the under face of each file end. Each pin 18" is preferably straight sided and of a size to provide a close fit between the straight parallel sides of the coacting slot l9, and each is preferably slightly bevelled at its free end to facilitate entry thereof into the slot.

Various changes may be made in either embodiment of the invention hereinabove specifi- 'cally described without departing from or sacrificing the advantages of the invention as defined in the appended claims.

I claim:

1. A flexible abrasive device for abrading machines, said'device' comprising a flexible carrier, a succession of rigid abrasive elements attached directly to said carrier, each element extending lengthwise of said carrier and having an end swingable'clear of said carrier upon flexing the latter, and means on said carrier coacting with said ends of said elements for accurately registering the adjacent ends" of successive elements, said means and elements being relatively movable into and out of coacting relation by flexing said carrier toward and from a straight condition.

2. A flexible abrasive device for abrading machines, said device comprising a flexible carrier, a succession of rigid abrasive elements attached directly to said carrier intermediate their ends, said elements extending lengthwise of said carrier with their ends free to swing clear of said carrier upon flexing the latter, and means on said carrier movable into and out of guiding relation with said ends in response to flexing of said carrier and coacting with said ends to effect accurate registration of the latter upon straightening said carrier.

3. A flexible abrasive device for abrading machines, said device comprising a flexible carrier,

a succession of rigid abrasive elements attached intermediate their ends directly to said carrier with said ends free to swing clear of said carrier upon flexing the latter, and guide keys on said carrier movable into and out of guiding relation with said ends of said elements in response to flexing of said carrier toward and from a straight condition, said keys being effective to accurately register the adjacent ends of successive elements in the straight condition of said carrier.

4. A flexible abrasive device for abrading machines, said device comprising a flexible carrier,

a succession of rigid abrasive elements extending lengthwise of said carrier and attached intermediate their ends, directly to the outer face of said carrier, aligned slots in the adjacent ends of successive elements, and a plurality of guide keys on said carrier, each key being disposed to enter both. slots in adjacent ends of successive elements and to thereby register said adjacent ends, the ends of said elements being swingable clear of said carrier and said keys upon flexing of said carrier.

5. In an abrading machine having a pair of spaced aligned pulleys, the combination of a flexible carrier adapted to travel around said pulleys, a succession of rigid abrasive elements each secured directly to the outer face of said carrier at a point intermediate the ends of said elements, means projecting from the face of said carrier and engaging slots formed in the under surfaces of said abrasive elements at both ends thereof, to maintain said elements in substantial alignment, the ends of said abrading elements being free to move out of contact with said carrier and said projecting means upon flexing of said carrier about said pulleys.

6. In an abrading machine including a pair of spaced aligned pulleys, the combination of a flexible carrier adapted for travel around said pulleys,ta succession of rigid abrasive elements each secured directly to the outer face of said carrier at a point intermediate the ends of said elements, interengaging means on the outer face of said carrier and on the under side of each element adjacent the ends thereof, said interengaging means being separable to permit movement of saidelements out of contact with said carrier as said carrier is flexed around said pulleys.

BENJAMIN GRO B. 

